摘要:

A comparison was made of the probing behavior of reproductively diapausing winter-form pear psylla,Psylla pyricolaFoerster (Homoptera: Psyllidae), given access to leaves ofPyrus communiscv. Winter Nellis (pear, the sole reproductive host) andPrunus persicacv. Lovell (peach, a transitory host on which psylla do not reproduce). Winter-form pear psylla ingested predominantly from the phloem, xylem, and spongy parenchyma cells of pear and peach leaves. The elapsed time to first probe was significantly longer when insects were given access to peach than when given access to pear, yet the mean proportion of total probe time spent ingesting when various peach and pear leaf cell types were probed did not differ significantly, with the exception of spongy parenchyma cells. These results suggest that preprobe stimuli mediate discrimination between reproductive and transitory host plants by winter-form psylla. The possible sensory mechanisms underlying host acceptance and discrimination between leaf cell types by winter-form pear psylla, as well as the epidemiological implications of these data for pear decline, are discussed.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.675

出版商:Oxford University Press    

年代:1988

数据来源: OUP

摘要:

Ovarian dynamics indicate that the celery looper,Syngrapha falcifera(Kirby), does not overwinter in Iowa. Additionally, early spring population trends, ovarian dynamics, and associated weather patterns strongly imply that the celery looper is a migrant into the state. Estimated celery looper development requirements of 377 degree-days per generation with developmental thresholds of 8.3°C minimum and 32.6°C maximum were determined from field data by the least-variability method. Developmental requirements and ovarian dissections allowed the discrimination of four complete generations in 1984 through 1986.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.679

出版商:Oxford University Press    

年代:1988

数据来源: OUP

摘要:

A life table was developed for two consecutive univoltine generations of the red sunflower seed weevil,Smicronyx fulvusLeConte, a major pest of cultivated sunflower in North Dakota. A mean mortality of 86.9% for fifth instar and pupa in the soil was the highest for all life stages. A 94.6% generation mortality indicates a slightly declining weevil population for the two years of the study.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.685

出版商:Oxford University Press    

年代:1988

数据来源: OUP

摘要:

Ovipositional preferences of the European corn borer (ECB),Ostrinia nubilalis(Hübner), for several phenological stages of field corn and cotton in field cages were examined in North Carolina from 1981 through 1983. Adults preferred to oviposit on field corn in the silking stage, then shifted to cotton (especially flowering cotton) when the corn silks dried and plants senesced.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.688

出版商:Oxford University Press    

年代:1988

数据来源: OUP

摘要:

An oviposition stimulant bioassay was developed for the sweetpotato weevil,Cylas formicarius elegantulus(Summers), using sweet potato storage root cores with the outer periderm exposed or that had their surface compounds removed with methylene chloride. The weevils laid significantly (P≪ 0.05) more eggs on the control cores and extracted potatoes on which the extract had been reapplied than on extracted cores without additions, indicating the presence of an oviposition stimulant.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.691

出版商:Oxford University Press    

年代:1988

数据来源: OUP

摘要:

The black vine weevil,Otiorhynchus sulcatus(F.), preferred to oviposit in containers with Japanese yew,Taxus cuspidataSiebold and Zuccarini, cv. Densa, foliage over 10 other plant species when given alternating 5- or 7-d exposures. Host experience of larvae or prereproductive adults generally had no effect on their overall preference forTaxus.Weevils did not differentiate between pairs of most nonhosts but exhibited some preference for strawberry,Fragaria ananassaDuchesne. Females had to contactTaxusfoliage to be stimulated to oviposit. Antennectomized weevils were able to differentiate betweenTaxusandIlex crenata compactaThunberg foliage, but they laid a greater proportion of their eggs onIlexthan intact weevils. It is suggested thatT. cuspidataand possibly strawberry foliage contain an oviposition stimulant for the black vine weevil which is perceived only by contact or feeding.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.694

出版商:Oxford University Press    

年代:1988

数据来源: OUP

摘要:

Life tables were constructed for the asparagus aphid,Brachycorynella asparagi, caged on different ages of asparagus foliage. In trial one of the experiment, foliage age ranged from 16 to 72 d. As foliage aged, the intrinsic rate of aphid increase declined, generation time increased, projected population size decreased, prereproductive and reproductive periods lengthened, and maximum number of offspring per day declined. In trial two, foliage age ranged from 15 to 138 d. Only 3 of 10 aphids survived to reproduce on 97-d-old foliage, and none reproduced on 138-d-oldfoliage. In trial two, prereproductive period was lengthened and day of maximum reproduction was delayed by increased foliage age. The net reproductive rate was not significantly affected in either trial. It appears that the quality of asparagus as food for the asparagus aphid declined as foliage aged.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.699

出版商:Oxford University Press    

年代:1988

数据来源: OUP

摘要:

The longevities of five commercial lures and one experimental lure for apple maggot were determined in laboratory and field tests in Utah. The Pherocon AM panel exhibited a reduced fly capture efficiency when aged for 9 d before use, which correlated well with the 5-d longevity observed in laboratory tests. The apple volatile lures made by Consep Membranes and Great Lakes IPM lasted at least 40 d in laboratory and field tests. However, the Ladd Industries rubber septum was found to last only about 4 d in the same tests. The implications of lure longevity on the present confusion over trap choice for monitoring apple maggot are discussed.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.704

出版商:Oxford University Press    

年代:1988

数据来源: OUP

摘要:

The parasites of second- and third-instar Japanese beetles,Popillia japonicaNewman, and associated scarab larvae were identified in turf samples from 49 locations in Connecticut during the fall of 1986. Four of the seven species of scarab larvae encountered were introduced and accounted for 91% of the sample population. Recovered parasites included three species of protozoa, two bacteria, a rickettsia, and a fungus. The most common protozoa, cephaline eugregarines, were found in the gut of Japanese beetles from 42 locations, and in four other host species. A microsporidium,Ovavesicula popilliaeAndreadis and Hanula, was found in Japanese beetles from 34 sites. Overall, 25% of the larvae were infected, but prevalence was 80–90% in some locations. AnAdelinasp. infecting 19% of the Asiatic garden beetles,Maladera castanea(Arrow), was found at six locations and in two other scarab species. This is the first record ofAdelinasp. in these hosts. The bacteriaBacillus popilliaeDutky andB. lentimorbusDutky and a rickettsia,Rickettsiella popilliae(Dutky and Gooden) Philip, were also recovered from grubs.R. popilliaewas recovered from five species. Two of the infected species, the Asiatic garden beetle and the European chafer,Rhizotrogus majalis(Razoumowsky), are new records as natural hosts for this pathogen. The incidence ofB. popilliae(3.5%) was comparable with previous reports from Connecticut. The fungus,Metarhizium anisopliae(Metch.), infected 1.2% of the Japanese beetles.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.709

出版商:Oxford University Press    

年代:1988

数据来源: OUP

摘要:

The suitability of lemon,Citrus limon(L.) Burm. cv. Lisbon, for egg production by the citrus red mite,Panonychus citri(McGregor), was compared with that of mandarin orange,Citrus unshiuMarkovitch cv. Satsuma in the field and laboratory over a 15-mo period. The two plant species were most suitable during the spring (April–June), when mites generally are most abundant in the field, and did not differ significantly in suitability during this time. In laboratory experiments, the suitability of both species declined during the summer and fall, but mandarin declined most. Thus, lemon was the most suitable host except during the spring. Mandarin foliage was generally richer in soluble protein and free amino acid concentrations throughout the study. Variation in quantities of soluble protein and free amino acids was weakly and inconsistently related to variation in egg production between species and within species over time. Variation in egg production was not associated with the greater number of leaf flushes on lemon. Differences in host suitability among citrus species may play only a minor role in variation in the status of the citrus red mite as a pest among different citrus-growing regions.

ISSN:1754-5692    

DOI:10.1093/ee/17.4.715

出版商:Oxford University Press    

年代:1988

数据来源: OUP